SC1110

SINK AND SOURCE DC/DC CONTROLLER FOR

TERMINATION POWER SUPPLY APPLICATIONS

© 2000 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA 91320

PRELIMINARY - October 9, 2000

1

DESCRIPTION

The SC1110 is a low-cost, full featured, synchronous

voltage-mode controller designed to generate termina-

tion voltage in double data rate (DDR) memory sys-

tems and other applications where wide data bus need

to be actively terminated. Synchronous control of the

MOSFET half bridge allows power flowing bi-

directionally. The termination voltage can be tightly

regulated to track the chipset voltage, i.e. to be exactly

50% of that at all times.

The SC1110 is ideal for low cost implementation of ter-

mination voltage supplies. SC1110 features include

temperature compensated voltage reference, triangle

wave oscillator and current sense comparator circuitry,

and allows the use of inexpensive N-channel power

switches.

The SC1110 operates at a fixed 250kHz, providing an

optimum compromise between efficiency, transient

performance, external component size, and cost.

FEATURES

tion schemes

ter than ±80mV

mode

performance

APPLICATIONS

systems

TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com

DEVICE

(1)

PACKAGE

TEMP. RANGE (T

SC1110CSTR

SO-14

0 - 125°C

ORDERING INFORMATION

Note:

(1) Only available in tape and reel packaging. A reel

contains 2500 devices.

TYPICAL APPLICATION CIRCUIT

Q1

Si9426DY

Q2

Si9426DY

R8

2.2

R3

10

L1

800 nH

D1

MBRM120

C6

1.0

C12-14

3 x 560uF

C10,11

2 x 560uF

R6

4.7k

C2

0.1

C4

0.022

C1

0.01

R2

1.24k

REFOUT

SS/ENBL

+

_

+

_

Vin 2.5V

Vout = 1.25V @ 7A

+5Vcc

R7

2.2

C8,9

2 x 10uF

C7

1.0

C5

0.047

C15-24

10 x 10uF

C10-14: Sanyo, 4SP560M

C8,9,15-24: TDK, CC3216AX5R0J106K

Q1,Q2 options: Si9426DY, FDS6890A, IRF7401

D1: ON Semi (Motorola)

L1: Panasonic, ETQP6F0R8L or Falco, QPIP1205-809-3

R4

1k

R5

1k

C3

0.1

VCC

1

REFOUT

14

SS/ENBL

2

OCSET

3

GND

5

PHASE

6

DL

7

DH

8

BSTH

9

BSTL

10

COMP

11

SENSE

12

REFIN

13

PWRGD

4

U1

SC1110

PWRGD

R1

5k

C25

0.1